The first commercially attractive cellular telephones or terminals were introduced in the market at the end of the 1980's. Since then, a lot of effort has been made in making smaller terminals, with much help from the miniaturisation of electronic components and the development of more efficient batteries. Today, numerous manufacturers offer pocket-sized terminals with a wide variety of capabilities and services, such as packet-oriented transmission and multiple radio band coverage.
In order to attract customers the terminal manufacturers have therefore taken further measures to strengthen their position in the competition, one such being to offer terminals with detachable covers or covers. If a user wishes to change the outer appearance of his communication terminal, he can simply buy a new cover of the desired kind. The old cover is preferably released by a simple grip without the aid of tools, where after the new cover can be snapped on. A detachable cover is generally a fairly simple element, essentially formed from a single piece of plastic or possibly metal. The cover may represent only the front side of the terminal, i.e. the side of the terminal carrying the user interface generally comprising a terminal display and keypad, a microphone and a loudspeaker. In such a design, the cover forms a separate part of the cover of the terminal, or optionally an auxiliary part to be attached outside the cover. Alternatively, the cover may include more than one piece, e.g. a front piece and a back piece devised to substantially enclose the terminal. The detachable covers are often provided in different colours, and also with more advanced patterns such as logos or images.
The detachable covers of the prior art mainly create an aesthetic effect, changing the visual appearance of the terminal. However, the requirements on the detachable and exchangeable covers are usually conflicting. The covers are should be rigidly attached during usage, but be easily disassembled once the user chooses to chance to another set of covers. Preferably, disassembly of the covers should be possible without the need for any tools or similar.
A number of products that allow personalisation by exchanging covers are available on the market today, although the level of personalisation differs. The T300 by Sony Ericsson® features an exchangeable front cover, while the 8310 and the 6510 by Nokia® have exchangeable front covers as well as battery covers. These two Nokia phones are basically the same but with different cosmetic covers.